An evidence-based validation of traditional Chinese medicine syndromes.

Objectives: A standard description regarding the diagnosis of traditional Chinese medicine (TCM) syndromes based on validated evidence is needed for education, practice and evaluation of TCM syndrome-specific treatments. We studied whether an evidence-based four-step approach proposed for the validation of TCM syndromes could validate Kidney-Yin deficiency syndrome (KDS-Yin) and Kidney-Yang deficiency syndrome (KDS-Yang) in middle-aged women with menopausal symptoms.

Methods: TCM classic and contemporary literature were reviewed for the symptoms and the domain changes of KDS-Yin and KDS-Yang. Factor analysis was used to explore whether these symptoms could be grouped according to their mutual relationships in a sample of women. Latent tree models were constructed based on the factor loadings and justifiability by the theory, and were tested by structural equation modelling on another sample of women.

Results: The symptoms and domain changes were reviewed from the TCM literature. Exploratory factor analysis (EFA) identified symptom patterns on a sample of 236 women. Based on the findings and the TCM literature, latent tree models of KDS-Yin and KDS-Yang, showing their domain changes and domain symptoms, were constructed and could be confirmed by structural equation modelling on a sample of 323 women.

Conclusion: KDS-Yin and KDS-Yang in middle-aged women with menopausal symptoms were validated and the four-step approach may be used to validate TCM syndromes.